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	hartrees
Energy at 0K	-153.353140
Energy at 298.15K	-153.352448
HF Energy	-153.353140
Nuclear repulsion energy	77.397807

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)
1	Σ_g	3489	3350	0.00
2	Σ_g	2310	2218	0.00
3	Σ_g	926	890	0.00
4	Σ_u	3491	3351	202.70
5	Σ_u	2132	2047	3.01
6	Π_g	671	645	0.00
6	Π_g	671	645	0.00
7	Π_g	539	517	0.00
7	Π_g	539	517	0.00
8	Π_u	680	653	98.56
8	Π_u	680	653	98.56
9	Π_u	239	229	9.35
9	Π_u	239	229	9.35

Atom	x (Å)	y (Å)	z (Å)
C1	0.000	0.000	0.681
C2	0.000	0.000	-0.681
C3	0.000	0.000	1.887
C4	0.000	0.000	-1.887
H5	0.000	0.000	2.950
H6	0.000	0.000	-2.950

	C1	C2	C3	C4	H5	H6
C1		1.3625	1.2053	2.5678	2.2692	3.6317
C2	1.3625		2.5678	1.2053	3.6317	2.2692
C3	1.2053	2.5678		3.7731	1.0639	4.8370
C4	2.5678	1.2053	3.7731		4.8370	1.0639
H5	2.2692	3.6317	1.0639	4.8370		5.9009
H6	3.6317	2.2692	4.8370	1.0639	5.9009

atom1	atom2	atom3	angle		atom1	atom2	atom3	angle
C1	C2	C4	180.000		C1	C3	H5	180.000
C2	C1	C3	180.000		C2	C4	H6	180.000

All results from a given calculation for C₄H₂ (Diacetylene)

using model chemistry: HSEh1PBE/TZVP

States and conformations

	Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Number	Element	Mulliken
1	C	-0.060
2	C	-0.060
3	C	-0.124
4	C	-0.124
5	H	0.184
6	H	0.184

<r²>	78.365
(<r²>)^1/2	8.852

All results from a given calculation for C4H2 (Diacetylene)

using model chemistry: HSEh1PBE/TZVP

States and conformations

All results from a given calculation for C₄H₂ (Diacetylene)